1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #include <stdbool.h> 3 #include <stdio.h> 4 #include <stdlib.h> 5 #include <stdarg.h> 6 #include <string.h> 7 #include <sys/types.h> 8 #include <sys/stat.h> 9 #include <sys/mman.h> 10 #include <fcntl.h> 11 #include <unistd.h> 12 #include <elf.h> 13 #include "../../include/linux/module_symbol.h" 14 15 #include "list.h" 16 #include "elfconfig.h" 17 18 /* On BSD-alike OSes elf.h defines these according to host's word size */ 19 #undef ELF_ST_BIND 20 #undef ELF_ST_TYPE 21 #undef ELF_R_SYM 22 #undef ELF_R_TYPE 23 24 #if KERNEL_ELFCLASS == ELFCLASS32 25 26 #define Elf_Ehdr Elf32_Ehdr 27 #define Elf_Shdr Elf32_Shdr 28 #define Elf_Sym Elf32_Sym 29 #define Elf_Addr Elf32_Addr 30 #define Elf_Section Elf32_Half 31 #define ELF_ST_BIND ELF32_ST_BIND 32 #define ELF_ST_TYPE ELF32_ST_TYPE 33 34 #define Elf_Rel Elf32_Rel 35 #define Elf_Rela Elf32_Rela 36 #define ELF_R_SYM ELF32_R_SYM 37 #define ELF_R_TYPE ELF32_R_TYPE 38 #else 39 40 #define Elf_Ehdr Elf64_Ehdr 41 #define Elf_Shdr Elf64_Shdr 42 #define Elf_Sym Elf64_Sym 43 #define Elf_Addr Elf64_Addr 44 #define Elf_Section Elf64_Half 45 #define ELF_ST_BIND ELF64_ST_BIND 46 #define ELF_ST_TYPE ELF64_ST_TYPE 47 48 #define Elf_Rel Elf64_Rel 49 #define Elf_Rela Elf64_Rela 50 #define ELF_R_SYM ELF64_R_SYM 51 #define ELF_R_TYPE ELF64_R_TYPE 52 #endif 53 54 #if KERNEL_ELFDATA != HOST_ELFDATA 55 56 static inline void __endian(const void *src, void *dest, unsigned int size) 57 { 58 unsigned int i; 59 for (i = 0; i < size; i++) 60 ((unsigned char*)dest)[i] = ((unsigned char*)src)[size - i-1]; 61 } 62 63 #define TO_NATIVE(x) \ 64 ({ \ 65 typeof(x) __x; \ 66 __endian(&(x), &(__x), sizeof(__x)); \ 67 __x; \ 68 }) 69 70 #else /* endianness matches */ 71 72 #define TO_NATIVE(x) (x) 73 74 #endif 75 76 #define NOFAIL(ptr) do_nofail((ptr), #ptr) 77 78 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) 79 80 void *do_nofail(void *ptr, const char *expr); 81 82 struct buffer { 83 char *p; 84 int pos; 85 int size; 86 }; 87 88 void __attribute__((format(printf, 2, 3))) 89 buf_printf(struct buffer *buf, const char *fmt, ...); 90 91 void 92 buf_write(struct buffer *buf, const char *s, int len); 93 94 struct module { 95 struct list_head list; 96 struct list_head exported_symbols; 97 struct list_head unresolved_symbols; 98 bool is_gpl_compatible; 99 bool from_dump; /* true if module was loaded from *.symvers */ 100 bool is_vmlinux; 101 bool seen; 102 bool has_init; 103 bool has_cleanup; 104 struct buffer dev_table_buf; 105 char srcversion[25]; 106 // Missing namespace dependencies 107 struct list_head missing_namespaces; 108 // Actual imported namespaces 109 struct list_head imported_namespaces; 110 char name[]; 111 }; 112 113 struct elf_info { 114 size_t size; 115 Elf_Ehdr *hdr; 116 Elf_Shdr *sechdrs; 117 Elf_Sym *symtab_start; 118 Elf_Sym *symtab_stop; 119 unsigned int export_symbol_secndx; /* .export_symbol section */ 120 char *strtab; 121 char *modinfo; 122 unsigned int modinfo_len; 123 124 /* support for 32bit section numbers */ 125 126 unsigned int num_sections; /* max_secindex + 1 */ 127 unsigned int secindex_strings; 128 /* if Nth symbol table entry has .st_shndx = SHN_XINDEX, 129 * take shndx from symtab_shndx_start[N] instead */ 130 Elf32_Word *symtab_shndx_start; 131 Elf32_Word *symtab_shndx_stop; 132 133 struct symsearch *symsearch; 134 }; 135 136 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */ 137 static inline unsigned int get_secindex(const struct elf_info *info, 138 const Elf_Sym *sym) 139 { 140 unsigned int index = sym->st_shndx; 141 142 /* 143 * Elf{32,64}_Sym::st_shndx is 2 byte. Big section numbers are available 144 * in the .symtab_shndx section. 145 */ 146 if (index == SHN_XINDEX) 147 return info->symtab_shndx_start[sym - info->symtab_start]; 148 149 /* 150 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of 151 * the way to UINT_MAX-255..UINT_MAX, to avoid conflicting with real 152 * section indices. 153 */ 154 if (index >= SHN_LORESERVE && index <= SHN_HIRESERVE) 155 return index - SHN_HIRESERVE - 1; 156 157 return index; 158 } 159 160 /* 161 * If there's no name there, ignore it; likewise, ignore it if it's 162 * one of the magic symbols emitted used by current tools. 163 * 164 * Internal symbols created by tools should be ignored by modpost. 165 */ 166 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) 167 { 168 const char *name = elf->strtab + sym->st_name; 169 170 if (!name || !strlen(name)) 171 return 0; 172 return !is_mapping_symbol(name); 173 } 174 175 /* symsearch.c */ 176 void symsearch_init(struct elf_info *elf); 177 void symsearch_finish(struct elf_info *elf); 178 Elf_Sym *symsearch_find_nearest(struct elf_info *elf, Elf_Addr addr, 179 unsigned int secndx, bool allow_negative, 180 Elf_Addr min_distance); 181 182 /* file2alias.c */ 183 void handle_moddevtable(struct module *mod, struct elf_info *info, 184 Elf_Sym *sym, const char *symname); 185 void add_moddevtable(struct buffer *buf, struct module *mod); 186 187 /* sumversion.c */ 188 void get_src_version(const char *modname, char sum[], unsigned sumlen); 189 190 /* from modpost.c */ 191 char *read_text_file(const char *filename); 192 char *get_line(char **stringp); 193 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym); 194 195 enum loglevel { 196 LOG_WARN, 197 LOG_ERROR, 198 LOG_FATAL 199 }; 200 201 void modpost_log(enum loglevel loglevel, const char *fmt, ...); 202 203 /* 204 * warn - show the given message, then let modpost continue running, still 205 * allowing modpost to exit successfully. This should be used when 206 * we still allow to generate vmlinux and modules. 207 * 208 * error - show the given message, then let modpost continue running, but fail 209 * in the end. This should be used when we should stop building vmlinux 210 * or modules, but we can continue running modpost to catch as many 211 * issues as possible. 212 * 213 * fatal - show the given message, and bail out immediately. This should be 214 * used when there is no point to continue running modpost. 215 */ 216 #define warn(fmt, args...) modpost_log(LOG_WARN, fmt, ##args) 217 #define error(fmt, args...) modpost_log(LOG_ERROR, fmt, ##args) 218 #define fatal(fmt, args...) modpost_log(LOG_FATAL, fmt, ##args) 219